5 Answers
5

The \title, \author and \date macros are saving their argument into \@title, \@author, and \@date, respectively. You can use this macros after \makeatletter. Afterwards use \makeatother. Note that they are cleared by \maketitle.

\title{Example}
\author{Me}
\date{\today}
% ...
\makeatletter
\begin{titlepage}
The title is \@title
It was written by \@author\space on \@date
\end{titlepage}
\makeatother

The titling package provides various user-friendly ways to modify title pages.

It provides the macros \thetitle, \theauthor and \thedate which can be reused anywhere in your document.

It allows you to have multiple instances of \title, \author and \date and \maketitle itself in a single document. (If you don't use titling, \maketitle clears the values of \@title, \@author and \@date [cf. Martin's answer] after it has used them.)

It also provides various hooks for modifying the formatting of all of the component parts.

Well, for me, it wasn't. I guess it's because in learning LaTeX, I used \title{...} etc. before I used any packages, so they came first in the source; then, I liked seeing the meta-data at the very top of the source. The question I linked to describes the first (and so far only) time this meant trouble for me. Your "1) setup 2) content" approach makes a lot of sense, though. (Obviously, the note wasn't meant for you personally, but as a general pointer.)
–
doncherrySep 4 '11 at 17:11

I understand your question as follows: How can I access the values of the title, author, and date fields somewhere in the document. I suggest the following MWE as an answer, which dispenses with the need to use \makeatletter ... \makeatother outside of the preamble:

\def\myauthor{Author} % Author
\def\mycoauthor{} % co-author
\def\mytitle{Title} % title
\def\mydate{Date} % date
%....
\begin{titlepage}
The title is \mytitle
It was written by \myauthor on \mydate
\end{titlepage}